Where did new cities appear in the Middle Ages?

In the Middle Ages, new cities could arise:

1. At the intersection of land trade routes. Such cities developed mainly due to transit trade and fairs;

2. On the coast, if a suitable place was presented (deep enough, closed from storms and close to waterways);

3. Near mineral deposits where families of workers, artisans, wardens, merchants settled.

4. In rural areas, acting as a kind of center of this area;

5. Around the border fortress.